About Ayana 2012

Ayana is a two day event conducted by PES IT. It starts with tech talks on the first day followed by 24 hour hackthon, similar to Yahoo Open hackdays.

Introduction to hardware hacking using Arduino

In my talk, I first talked about why a software hacker should look into hardware hacking. I then followed it by a brief introduction to Arduino, using the famous Blink program.

After that I was talking about different ways by which you can make Arduino talk to Internet and mobile phones like Android.

In the end I also gave out some hack ideas for the participants.

Slides

I have uploaded the slides that I used during the talk to my slideshare account. I have also embedded it here for easy reference.

The talk went well and there were lot of questions after the event, which is generally a good sign

Buying Arduino in Bangalore

As it used to happen in my other talks about Arduino, even today lot of people asked me about places where they can buy Arduino in Bangalore. I have already collect a list of places from where you can buy Arduino in Bangalore. You can refer to that page, in case you are planning to buy Arduino in Bangalore.

I started playing around with Dart for a couple of weeks now and so far, I kind of like the language, even though there are couple of bugs and some major features missing. That’s understandable since the language is still a technical preview.

Hacks

The following are some of the notable hacks from the hackthon

Snake Game by Sundar (it’s not Sudar )

It’s the classic snake game implemented in HTML5 using Dart. You can checkout a hosted version and the source code is available at github.

Charting Library

This is a charting library which allows you to create both pie and bar charts using Dart. You can checkout the source code in github.

Mocking library for Dart

It is a simple mocking library which allows you to write mocks to test Dart code. I personally liked this project very much.

Tbilisi hackthon

GTUG Tbilisi is planning to have a Dart hackthon like the one we had in Bangalore and tonight I am going to do a hangout session with them going over the Dart language and how we did our hackthon. You can check out the slides which I prepared for the event below

On the whole, Dart is a good language which you can use to create complex web applications. But it’s not yet ready for prime time use yet.

After poking around a bit, I found that Dart supports making Rest calls using XMLHttpRequest object, similar to JavaScript. I quickly tried to make a YQL call using that object.

The following is the bulk of the code. It is exactly how you do it in plain JavaScript.

URLEncoding

The only place I found a problem, was that Dart doesn’t have a URLEncoder yet. You have to emulate the URLEncoding done in JavaScript. I hope Dart gets its own URLEncoder soon.

Full source code

I have uploaded the full source code to github and added a couple of other examples as well. Check it out.

I searched the dart:html, dart:uri and dart:io packages and found that none of them have the method to do URLEncoding.

I then posted about it in stackoverflow and then later found that, right now the only way to do URLEncoding is to emulate the encodeURL() function of JavaScript. Someone from Google has already done it. I just copied the file and placed inside my Dart project and then used the following line in my dart file.

#import("EncodeDecode.dart");

Although it works right now, I would really like to see this as part of the dart:uri package. Let’s see if someone from the Dart team is listening to this.

Changes

The following are the changes that I have made to the Plugin

• Ability to exclude current post/page
• Moved caching logic to widget
• Added Lithuanian translations

Ability to exclude current post/page

One of the most requested feature in the Plugins was to have the ability to exclude the current post in the listing. This could happen when ever you are including the tag of the current post also in the list of tags.

Now I have added an option in the widget to exclude the current post or page.

This option is also available even if you are using either the template tag or the shortcode

Moved caching logic to widget

I have cleaned up the logic which I was using to cache the DB queries used by the Plugin. If you are using the widget, then the output of the widget itself is cached. If for some reason, you don’t want to the widget to cache the queries you can disable it as well.

But if you are using the shortcode or the template tag, then you have to manually cache the output or the db queries.

Dev Time

This release took me about 3.5 hours of development time. You can find more details about the dev time tracking which I have recently started doing in a separate blog post.

Download

You can download the latest version of the Plugin from the Plugin’s home page.

Feedback

Try out the Plugin and if you have any comments or if you want to report any bugs, please leave a comment below.

Stay updated

I would be posting updates about this Plugin in my blog and in Twitter . If you want to be informed when new version of this Plugin is released, then you can either subscribe to this blog’s RSS feed or follow me in Twitter .

Some of them are really popular. For instance my Bulk Delete WordPress Plugin has been downloaded for nearly 100,000 times. The flip side of it is that these pet projects have some additional baggage as well. Support questions, regular updates, feature requests etc can be sometimes very time consuming.

I always wanted to know the projects, which takes up most of my free time, but didn’t had any metrics or logs. So I have started to track the amount of time I am spending on each of these projects.

The advantage of this is that, now I know which project are real time hogs and can have some metrics to decide on whether it is worth spending time on those projects or not. I am also going to add this data to the project readme files, so that people who use it might also know the amount of time and effort I have put it on those projects

I have already started this and the recent release of my Bulk Delete WordPress Plugin had this metrics. I have spent close to 11 hours for releasing the update to the Plugin.

Let’s see how this new experiment turns out to be.

BTW do you guys also track your time spent on pet projects? If yes, then share your experiences as well.

Like the previous updates, this feature was also requested by the users of the Plugin. So if you have any feedback or feature request, don’t hesitate to contact me, I will try to add them to the Plugin.

New features

The following are the new features that are supported by the Plugin

• Ability to delete posts by permalink. This features was written by Martin Capodici
• Major UI revamp. Let me know if you have any feedback about the new UI.
• Added debug information, which should help you to debug issues related to your server.
• Added roles and capabilities for menu.

Bug Fixes

The following are some of the bug fixes which have gone into the releases

• Fixed issues with translations
• Fixed a major issue in the way how dates were handled
• Fixed CSS issues in IE

Translations

The following are the different languages for which translations have been added. If you are willing to translate the Plugin in your language, then you can find the pot file inside the language’s folder.

• Turkish
• Spanish
• Italian
• Bulgarian
• Russian
• Lithuanian

Dev Time

All these releases combinedly took me about 11 hours of development time. From this release on I have started tracking the amount of time I am spending on each release of my WordPress Plugins. There is a separate blog post, which explains the reasons why I track my development time.

Download

You can download the latest version of the Plugin from the Plugin’s home page.

Feedback

Try out the Plugin and if you have any comments or if you want to report any bugs, please leave a comment below.

Stay updated

I would be posting updates about this Plugin in my blog and in Twitter . If you want to be informed when new version of this Plugin is released, then you can either subscribe to this blog’s RSS feed or follow me in Twitter .

Instead of replying to them individually, I thought I would post about it here, so that it is useful for others as well.

Okay, to buy Arduino in Bangalore you have two options, either buy them offline (in a brick and motar shop) or buy them online.

Buying electronic components in Bangalore

In general you can find most of the electronic components that you need for your hobbyist projects in SP road in Bangalore. It is similar to Richee Street in Chennai. (I guess every city has a similar a similar road)

For people who are new to Bangalore, I have embedded a map of the place, which I am talking about below.

View Larger Map

Shops that sell Arduino in Bangalore

In SP road, I know the following shops that sell Arduino. There could be others as well, but these are the ones that I have personally bought Arduino from.

• NSK Electronics (price Rs. 1300, checked on 24-March-2012)
• Vishal Electronics (price Rs. 1300, checked on 24-March-2012)

NSK Electronics also sells Arduino clones for a much cheaper price. Once thing to keep in mind is that, these Arduinos don’t come with the USB cable. You have to buy them separately. Don’t forget to buy them as well. Last time I checked the price was around Rs 20.

Buying Arduino Online in India

If you are not in Bangalore or if you prefer to buy them online then you can buy them from one of the below shops.

• rhydolabz.com – I bought my first Arduino from them, way back in 2010
• 9circuits.com – They are slightly costly, but they have Arduino ADK boards as well.
• tenettech.com – They have lot of good tutorials and also have a clone as well.

Buying USB Host shield

I have not seen any shop selling USB Host Shield in Bangalore so far. The only option is to buy them online from Circuits@home

If you find a better option, then let me know in the comments below and I will add them to the article. Till then, best luck with your Arduino

About the talk

In the talk I mainly discussed about the way by which you can transfer data in and out of Android using the audio.

I also discussed about the ways by which you can read this data in Arduino from Android.

Slides

I have uploaded the slides, which I have used in the talk to my slideshare account. I have also embedded them below so that you can easily view them.

Video

I have embedded the video fo the talk as well. My talk starts after 20 minutes.

Discussion about my marriage card

Badrinath also gave talk about NFC in the meetup and he used my wedding card for my demo.

It’s kind of great to know that he remembered my marriage card even after my marriage which happened around 2 months before

Questions/Feedback

If you have a question or feedback/comments about my slide, then do let me know by leaving a comment below.

Buying Arduino in Bangalore

Lot of people asked me about buying arduino in Bangalore. Instead of answering them separately, I consolidated the different options in my blog. Let me know if I missed out any place.

I offered to adopt the Cron Debug Log Plugin because a couple of my own Plugins depend on cron and at times I need to debug if there are any issues with cron and this Plugin could be immensely helpful.

For those who don’t know, Cron Debug Log Plugin can used to debug remote calls made using Cron jobs in WordPress. It basically logs all unsuccessful wp_remote_post calls from Cron.

Ron was kind enough to accept my offer and gave me check-in access to the repo. Over the next few weeks, I am planning to make some modifications to the Plugin and add some features. If you want any specific feature in the Plugin, then do let me know and I will try my best to get it implemented.

Update

In addition to the above Plugin, I have also adopted the following Plugins.

• WordPress MU Theme Stats
• BP Blog Author Link

Even though it looked like a WordPress.org website, the url was different. I posted about it the wp-hackers mailing list and got the confirmation that is a phishing attempt to get your WordPress.org username and password.

If you get an email like below, be careful and don’t click the link or enter your username and password.

In addition follow the following steps to make sure you don’t compromise your account.

• Check the sending email address. It will always have a wordpress.org email address
• Check if the link text and the actual link are different.
• Make sure that the url of the page where you enter your password is always wordpress.org

You can also find more information about it from this forum thread.

WordPress.org has also sent the following email to all the Plugin developers regarding this issue.

Be vigilant and stay safe.

About the talk

The talk was mainly about using JavaScript in today’s world. I gave a brief about different frameworks and some suggestions on when to use each one of them.

It also covered using JavaScript in different scenarios. The following are the different use cases that I covered

• Using JavaScript in the Brower/client
• Using JavaScript in the server
• Using JavaScript to create mobile apps
• Using JavaScript to create desktop apps
• Using JavaScript to control devices connected to your computer

Slides

I have uploaded the slides which I used for the talk to my slideshare account. I have also embedded them below so that you can easily view them.

Questions/Feedback

If you have a question or feedback/comments about my slide, then do let me know by leaving a comment below.

Code

Let’s have a look at the code one more time.

You can also get the code from github.

Language

To start of the program was written in JavaScript. Whoever feels that JavaScript is not a *real* programming language, should first read these articles by Douglas Crockford.

Anonymous Function

The program starts with an anonymous function. This is not strictly needed by JavaScript syntax, but it is always considered a good practise to do and I generally do it in all JavaScript code that I write.

Object variables

Next, I create two instances of the Person object. This is similar to creating objects in any object oriented programming language.

Information about wedding

As you might have guessed, gettingMarried function is that one which prints the information about the marriage. I am passing a JSON object to the function as an argument with the required information.

Checking the responsibility

This is the main crux of the invitation. I am verifying the responsibility before the marriage and after the marriage.

If you look closely at the isResponsible function, you will note that it has a special condition, which will always return false for me, irrespective of my marital status. The hidden message is that, I will never change after marriage. It’s going to be month since I am married and I can say that I haven’t changed yet. Hoping that it continues for the rest of my life

I am not that good at writing stuff that needs to be put on the invitation card, so instead I did what I do best. I wrote code Yes both figuratively and literally Need proof? check the photographs.

Code

After deciding that I wanted to write code, I had to decide the language. Initially I thought of writing an HTML document with tags. But somehow I was not convinced that HTML is a real programming language (okay, I am not here for a language war ).

After giving some more thought on it, I decided to do it in JavaScript. It was also fitting that I do it in JavaScript, since I had been mostly a web developer through out my career.

After a few minutes I had the basic version. After a couple of revisions, I finally came up with this version.

Update: I have also posted an explanation of this code, if in case JavaScript is not your cup of tea.

Screenshot

After completing the program (which I nicknamed as the “program that changed my life”), I had to decide how to print it on the card. Navneet Nair, who works with me, suggested me to put a screenshot of my IDE with the code inside.

Even I liked the idea and that’s how I decided to take a screenshot of my IDE and have it printed as the card.

Vim/Vi

This was a pretty easy decision to make. I was typing the code in vim (macVim to be exact) and after trying out a couple of color schemes, I finally settled on the desert color scheme

Envelope

The next step was to design the envelope. I did a basic version in Photoshop, by picking up some quotes from the programmer Ryan Gosling meme and placing them in comic sans font I then asked Navneet if he would like to change anything. He looked at it and said that he would like to change everything He then did a quick design in Illustrator with the quotes and it came out very well.

NFC

I wanted to increase the geeky quotient of my wedding invitation a little more and that’s when I thought of embedding NFC chips in the card.

I first heard about NFC in Google’s IO last year and first saw it in action at DroidCon organized by HasGeek a couple of months before. I got hold of the person who had a stall at DroidCon and bought NFC stickers from him. They were a little costly but added a lot of geekness to the invitation

I then used the NFC Tag Writer Android app, to write a url on these NFC chips. If you tap an NFC enabled phone on my invitation, it will automatically open up a url which has information about my marriage, address and map to the marriage hall etc.

QR code

After doing the NFC stuff, I realized that most may not have a NFC enabled phone. That’s when I remembered about QR codes and generated one.

If I had time, I could have loved to customize the QR code a bit, but I didn’t have much time, so settled with the default one. You can find it at the back of the envelope.

Printing

After designing both the card and the envelope, I worked with a person from a print shop called PrintWorks who helped me get it printed. They were very helpful and delivered stuff on time and I highly recommend them.

Files

All my design files including the JavaScript source file are available at github. Feel free to use them for your own wedding (if you are not married yet )

Credits

There are couple of people who helped me to get this card designed and printed. A huge thanks to all of them.

• Navneet Nair, who works with me at Yahoo.
• Swamy from PrintWorks
• Kiran from hasgeek

Ohh, btw don’t forget to be present for my wedding

Update:  The following are some of the words which people said after seeing my invitation

• Amazing..
• The geeket card ever..
• Collector’s piece..
• I am gonna frame it ..

The following are the steps you need to follow.

• Plugin the ez430 USB dongle to the USB port of your Mac
• Pair the USB dongle and your ez430 watch
• Install python and Serial library
• Download or clone the ez430 tools repo from github
• Open up your ppt presentation
• Open terminal, navigate to the directory where you have ez430 tools package files and then type the command python ppt-mac.py
• And you are done

Let me know if you face any issues.

Recently one of the readers of my blog asked me how to do this in PHP and I was about to send him the code snippet. But then I thought of writing a blog article so that it will be useful for others as well.

So here we go.

The code is mostly self explanatory. The important part in the above code snippet is the “content Disposition” header.

Also since we are sending headers to the browser, we should not have started the output before this code executes. Otherwise we might get a “header already sent” error.

Personal Highlight

Well do I have to explain anything more?

For those who are still staring at the picture, yes I am “formally” engaged now My marriage is going to be on Feb 6^th 2012 (Just another 21 days to go)

Other highlights in 2011

Apart from the big personal update the following are some of the other highlights of 2011.

I started of the year by changing the permalink of my blog, had a most memorable day on top of a hill, released my first Arduino library, met my idol Doug for the first time in person, went to a couple of HackU events, released my gist-it WordPress Plugin, bought an interesting toy, created my pet bot Asimi, gave a couple of talks and finally experienced snowfall for the first time in my life.

Travel highlights

On the travel front I had a pretty good year. Following are some of my travel highlights

• Had a couple of treks
• Had an awesome bike ride across Karnataka
• Went to Malaysia
• Travelled to Kanpur, Delhi and Madras IITs
• Went to Goa for team outing
• Went to US on a Business trip and spent the weekends in SFO and LA
• Experienced my first snowfall
• And finally ended the year by going to Waynad on Christmas day.

Blog Stats

The following are my blog stats generated by my Year End stats WordPress Plugin.

At the starting of 2011, I wanted to increase the average size of the blog post that I write and I have succeeded in that.

But, when compared with the previous years, I have written fewer posts. Getting committed, travelling places and what else you can expect

With me getting married in 2012 I am not sure how much free time I will get, but I will definitely try my best to increase the count in 2012.

What’s in the card for 2012?

I am planning to spend more time on Android and Arduino stuff and also planning to enhance my pet bot Asimi. So expect some news about some cool projects.

Well, from the personal front, I am going to get married in 2012. Not sure what to expect out of it, but I am eagerly waiting for it. It’s kind of really exciting to realize that you have finally found someone with whom you are going to spend the rest of your life.

So how was 2011 for you?

But during my recent series of vacation, I witnessed snowfall for the first time ever in my entire life. It was one of those memorable moments in my life.

I was returning to India from US and my connecting flight was in Frankfurt, Germany and it is where I witnessed snowfall My flight got delayed a bit, but who cared

I didn’t know till then that snow while falling is soft. I always confused it with ice and assumed that it would be hard. When I got down from the flight, snow was floating in the air like a feather and it slowly kissed my skin. After it touched me, it slowly melted into water droplets. It was one of those memorable moments of my life, which you will remember for a long time.

Following are some of the photos that I took using my mobile, while enjoying the snowfall. I seriously wished that I had a decent camera with me at that time.

I also took these photos when my flight was over Iceland. You can see the frozen Atlantic ocean along the shore.

One more highlight of the trip is that, on four consecutive days, I boarded 4 flights, visited 6 airports and landed in 3 different countries in 3 different continents.

Let’s see if I get a chance to break my own record

Here is an outline of my plan for December. You yourself can figure out whether it is crazy or not

I am leaving to Goa on 1^st of December for team outing with my teammates and will be back to Bangalore on 3^rd night. Then the next day (4^th Dec) I am leaving to US on a Business trip. After spending two weeks there, I will be back to Bangalore on 21^st Morning. That evening I have a party at office. And after that, my office is closed for forced year-end vacation in which I will be travelling again (even though I haven’t finalized the place yet).

Ohh, by the way, did I mention that I have two weekends in US and I am planning to go Las Vegas in one weekend and to New York in the other.

And did I mention that I am missing two other outings from office because I don’t have enough days in December

Is it crazy enough

So if you sent me an email and if I haven’t responded back, then you know why

Meet you all in 2012 guys.

DroidCon

DroidCon is a developer conference and is part of world’s largest series of Android conferences. It happened at Bangalore on 18^th and 19^th of November.

Slides from my talk

I gave a talk about building robots using Android and Arduino. I explored the different ways by which you can make both Android and Arduino talk to each other, concentrating on the advantages and disadvantages of the different approaches.

When I find some free time, I will write about these approaches in more detail with code samples for each of them. So stay tuned

You can find the slides from my talk below.

Demo Video

Thanks to Arun for shooting this video

Demo source code

I also showed demo of my pet bot Asimi (more details about her later). You can download the source code and learn more about the bot from its homepage.

Update

Here is the video of my talk.

Yes you heard it right; it is a watch which you can (re)program

Features

The following are some of its features

• MSP430 with integrated <1GHz wireless transceiver
• On-board 3-axis accelerometer
• Pressure sensor
• Temperature sensor
• Battery voltage sensor
• 96-Segment LCD display driven directly by CC430
• Includes an eZ430 USB emulator that connects the Chronos to a PC for real-time, in-system programming and debugging
• Can be paired wirelessly with other RF based devices
• And of course you can see time as well

Video

Here is a video introducing the watch by Texas Instruments

I am currently working on a couple of ideas like integrating this watch with Arduino etc. So stay tuned. Meanwhile if you see me waving hands in the air, look carefully, I might be controlling the nearby devices using gestures

In the event, I talked about Yahoo Query Language (YQL) and thought of sharing the slides here so that it could be useful for others as well.

Slides

Code samples to access YQL

I am also trying to collect code snippets to access YQL in various languages. If your favourite language is not there then send me the code snippet and I will add it there.

Visit round Delhi

Before the event we also went around Delhi (especially Qutb Minar and India Gate) and you can check out the photos in my Flickr stream

But after the initial bliss went off, I was disappointed for two reasons. First you need an Android phone running Android version 2.3.4 or above. The second reason is that the original ADK kit is not compatible with the plain Arduino board. The downside of this is that all your existing Arduino Shields will not work with that board and not to mention you have to buy a rather expensive ADK kit. Now there is also an Arduino compatible ADK kit, but it is again expensive and it didn’t made sense for me to buy another Arduino board when I already had a bunch of them lying around.

Since it is based on Oleg’s USB Host Shield, I was trying to see if I can build a board with just plain Arduino board and Oleg’s USB Host Shield. It turns out it is possible and with the release of Oleg’s second version of the USB Host Library, it is much simpler.

Things you need

Any Arduino board.

You can use either UNO or Duemilanove. You can also use Arduino Mega, if you have one lying around. The advantage of using Mega is that you will have additional I/O pins.

USB Host Shield

You need a USB Host shield for Arduino. You can use the original shield by Oleg for $40, or you can buy a cheaper clone from sparkfun for $25. I recommend the original one by Oleg, since it doesn’t need an external power supply. If you are going to use Sparkfun’s version you need an external power supply. Also make sure you don’t buy the older version of Sparkfun shield. It has pins marked wrongly and you need to make changes to the library to make it work.

ADK compatible Android phone

You need an Android Phone which is ADK compatible, which means you need a phone which is running 2.3.4 or above. I tested this setup in Nexus S and it is working properly.

Sensors, LED’s, buttons

You would need additional sensors, LEDs or buttons to test the flow. To start with, you can just use some LED’s

Connections

Stack the USB Host shield on top of the Arduino board. Connect an LED on pin number 3. Connect your phone’s cable to the USB port of the shield.

Arduino Firmware

Download v2 of the USB Host Shield Library and place it in the library folder of your Arduino setup. Open the demokit_20 example sketch from the /examples folder and upload it to your Arduino board.

Android App

The Android demo app for ADK, can be found under the /app folder of the ADK package. Upload the app to your Android phone.

Testing it

Power on Arduino and connect your Android phone to the other side of the cable. You should see a dialog box, which asks you whether you want to launch the app. Click yes. Once the app is launched you can control the LED connected on pin 3, by moving the slider in the Android app.

Now enjoy your new cheaper ADK kit

You can find the slide that I used for the talk from my slideshare account. I have also embedded it below for quick browsing

Slides

Video

Demo source code

I also used a couple of demos for my talk. You can download the source code for all of them from my github account.

Hack night

Before the event, we also had a hack night, where we were trying to create some apps using JavaScript over a weekend. I created a small game prototype using socket.io. You can download the source for this as well from my github account.

Speaker Video

Here is the speaker video which hasgeek recorded before the event.

I was looking at various JavaScript solutions and finally found the CSS selectable property. But it was not working across different browsers. It took a considerable effort to make it work across different browsers.

I found this code while browsing through archives and thought of posting it here so that I know where to find it, if I need it and also it would be useful for others who want to do the same thing.

BTW, one quick disclaimer. Even I hate it when people make a particular position of text unselectable in a browser. So use it if it is really needed and also remember it is not fool-proof.

Well, let’s see the code then.